Roof supports suitable for use in mines



y 7, 1968 T. o. H. ANDREWS 3,381,480

ROOF SUPPORTS SUITABLE FOR USE IN MIN ES Filed Feb. 8, 1965 2Sheets-Sheet 1 A-r-roeuav May 7, 1968 T. 0. H. ANDREWS ROOF SUPPORTSSUITABLE FOR USE IN MINES 2 Sheets-Sheet 2 Filed Feb. 8, 1965 1 R H E 3kW l i w W z r m m m 9 Q 9 K Q m. WIJ. i 6m 'THQMAS 11H. ANDPEWS BYUnited States Patent 3,381,480 ROOF SUPPORTS SUITABLE FOR USE IN MINESThomas D. H. Andrews, Cheltenham, England, assignor to Dowty MiningEquipment Limited, Tewlresbury, England, a British company Filed Feb. 8,1965, Ser. No. 430,922 Claims priority, application Great Britain, Mar.10, 1964, 10,096/64 3 Claims. (Cl. 61-45) ABSTRACT OF THE DISCLOSURE Thepresent invention provides a roof support wherein two distinct anddifferent floor beams are rigidly, rather than flexibly, connectedtogether in laterally-spaced substantiallyparallel relationship byconnecting means of a particular construction, the whole being designedto afford a passageway of maximum area parallel to the working face ofthe mine for passage of air, and a corn struction such as will protect aminer who must move through the passageway from falling material. Tosuch ends one floor beam of a pair is of a length to carry, for example,two extendable props which cooperate to support a roof-engageablemember, whereas the other such floor beam is longer, and carries, forexample, three extendable props which themselves support an articulatedroofengageable member, of which one part is supported upon two of thethree props-these two cooperating with the two props of thefirst-mentioned floor beam to define an orthodox square--and the otherarticulated roofengageable member is supported upon the third of thethree props. Each prop mounting, but not the prop per se, is locatedsubstantially within its floor beam, whereby the passageway isobstructed to a minimum degree, and includes resilient means urging theprop to a predetermined angular position relative to the floor beam(some what as is suggested in Patent No. 3,250,507), while allowing theprop a limited amount of angular movement relative to the floor beam.

This invention relates to roof supports suitable for use in mines.

Three sides of each floor beam, for example the top and two sides, maybe formed from a single piece of material. The bases of the floor beamsand a part of the connecting means may be formed from a single piece ofmaterial.

The connecting means between the floor beams may include twosubstantially-horizontal vertically-spaced connecting plates and twosubstantially-vertical horizontalspaced connecting plates, theconnecting plates and adjacent sides of the floor beams being integrallyjoined to form a torsion box.

The props carried by the two floor beams may carry the sameroof-engageable member. Alternatively, and preferably, the props carriedby one floor beam may carry a first roof-engageable member, and theprops carried by the other floor beam carry a second roof-engageablemember.

Reference to the drawings One embodiment of the present invention willnow be described, by way of example, with reference to the accompanyingdrawings, of which FIGURE 1 is a plan view of a mine roof support,

FIGURE 2 is a side view of the roof support,

FIGURE 3 is a plan view of the lower part of the roof support, and

FIGURE 4 is a sectional view along the line 4-4 of FIGURE 3, with theprops and part of their mountings removed.

Detailed description With reference to the accompanying drawings, a roofsupport suitable for use in a coal-mine includes a floor beam 3 carryingtwo fiuid-pressure-operated telescopic props l, and the lower endportion of each prop 4 is mounted in a prop mounting 5 located withinthe floor beam 3. The prop mounting 5 includes resilient means of knowntype urging the prop 4 to a predetermined angular position relative tothe floor beam 3 while allowing the prop 4 a limited amount of angularmovement relative to the floor beam 3. The prop mounting 5 shown in thedrawing includes a series of p'recompressed rubber bodies 6 forming theresilient means, somewhat as shown in US. Patent 3,250,507. The twoprops 4 carry and are pivotally attached to .a roof beam 7.

The roof support also includes a second floor beam 8 carrying threefluid-pressure-dperated telescopic props 9, and the lower end portion ofeach prop 9 is mounted in a prop mounting, similar to the prop mounting5, located within the floor beam 8. The props 9 carry and are pivotallyattached to an articulated roof-engageable member formed by a forwardand a rear IOOlf beam 111, 12 respectively, connected together by apivotal connection 13. The roof beam 11 is carried by the front prop 9,and the roof beam 12 is carried by the middle and rear props 9.

The floor beams 3, 8 are rigidly connected together in laterallyspacedparallel relationship by connecting means which in effect are integralwith the two floor beams. In this embodiment the bases of the floorbeams 3, 8 and a part of the connecting means are formed by a singleplate-like base member 1%. The top and two sides of the floor beam 3 areformed from a single piece of material 15 which is appropriatelyU-sh'aped and welded along its edges to the base member 14. Similarly,the top and two sides of the floor beam 8 are formed from a single pieceof material 16 which is appropriately U-shaped and similarly welded tothe base member 14.

The portion of plate or base member 14 which extends between the twofloor beams 3, 8 forms a lower horizontal connecting plate 17 integralwith and rigidly spacing apart the bases of the beams. The connectingplate 17 forms one part of the connecting means, which connecting meansalso includes an upper horizontal connecting plate 18, a forwardvertical connecting plate 19 and a rear veritcal connecting plate 21.

The upper connecting plate 18 is welded to the tops of the floor beams3, 8. The forward vertical plate 19 extends between and is welded to thehorizontal plates 17, 18 and is also welded to the adjacent sides of thefloor beams 3, 8 at a position adjacent the rearward side of the frontprop 4 of the support unit 1 and the rearward side of the middle prop 9of the support unit 2. The rear vertical plate 2'1 extends between andis welded to the horizontal plates 17, 18 and is also welded to theadjacent sides of the floor beams 3, 8 at a position adjacent the rearends of the floor beams 3, 8.

A shield 22 has its lower portion bolted to two lugs 23 welded to therear ends of floor beams 3, 8, respectively, and its upper portionbolted to the upper ends of two struts 24 whose lower ends are bolted totwo lugs 25 welded to the tops of the floor beams 3, 8, respectively.The shield 22 reduces the likelihood of coal or other mined materialfalling between the props 4 and the props 9 from a position rearw ardlyof the roof support.

At a position in front of the forward vertical plate 19, lugs 26 areprovided for the attachment of a fluid-pressure-operated jack (notshown) to the roof support. In use of the roof support, the jack will beattached to an anchorage, for example a conveyor, so that the roofsupport can be advanced towards the anchorage by contracting the jack.The jack may be secured to the roof support in conventional manner, suchfor instance as is shown in US. Ser. No. 443,421, filed Mar. 29, 1965.

In use of the roof support in a mine, the two horizontal connectingplates 17, 18, the two vertical connecting plates 19, 21 and theadjacent sides of the fioor beams 3, 8 form a torsion box which resistsrelative movement of the floor beams 3, 8, as these floor beams areacted upon by diverse forces.

The floor beams 3, 8 and the connecting means form a rigid base in whichthe prop mountings 5 are located, and this rigid base has a relativelysmall height compared to the overall height of the roof support. Thusthe roof support has a relatively large passage for gas flow in adirection transverse to the length of the floor beams 3, 8. Also, thedescribed roof support possesses the necessary strength to functionsatisfactorily in a mine without being unduly heavy.

I claim as my invention:

1. An advanceable roof support including two floor beams, one of whichis longer than and has a forward portion thereof extending beyond theadvancing end of the other, means rigidly connecting said floor beams inlaterally spaced substantially parallel relationship, two extend'a bleprops carried generally upright on each floor beam, the four props beinglocated to define generally a square, a third prop carried on theaforesaid forward portion of the longer floor beam, in advance of theother two props thereon, a roof-engageable member carried on the twofirst-mentioned props on each floor beam, an additional roof-engageablemember carried on the aforesaid third prop on the longer fioor beam, andhingedly connected to the first mentioned roof engageable member on saidlonger floor beam, and a plurality of mountings, one for each prop oneach floor beam, and resilient means interposed between each prop andits mounting, acting to urge the prop into a predetermined angularposition relative to its floor beam.

2. The advanceable roof support according to claim 1 wherein the top andsides of each floor beam are formed by a single channel-shaped piece ofmaterial, and the two pieces of material are rigidly interconnected by aplate extending thereunder.

3. The advanceable roof support according to claim 1 'wherein themutually adjacent sides of the floor beams are rigidly interconnected bypairs of horizontally and vertically disposed plates forming a torsionbox therewith.

References Cited UNITED STATES PATENTS 3,270,510 9/ 1966 Walsh 6 145FOREIGN PATENTS 202,954 1959 Austria. 1,310,022 1962 France. 1,332,1921963 France.

972,561 1959 Germany.

OTHER REFERENCES DAS 1,090,159, 1960, German application, Carow et al.

JACOB SHA PIRO, Primary Examiner.

DAVID J. WTLLIAMOWSKY, Examiner.

